Removing check valve to vac advance canister on Chrysler Ign

Hey doods.
Welp the hulk is nearly together, and there are some interesting things going on with the vaccuum lines.

For one, there is a check valve going from the intake manifold to the FPR- so that it would never see "boost", which makes little sense since as it was originally NA, it would never make "boost" anyways. So obviously I'm removing that one, since I want the reg to see boost and raise the fuel pressure accordingly. I'm confident it won't screw up the regulator, as I've had them apart before and know how the spring works, and it's no different between NA and Turbo mechanically, just a different spring rate.

BUT, there is another check valve. With my white distributor cap (pre-EZK) chrysler ignition the ignition computer is on the pass side fender, clipped to the washer fluid reservoir (or coolant, I never took careful note and the car isn't here in front of me, but I digress...) anyway it has one of those round sorta canister thingies on it, like a 240T Distributor has on it for the intake manifold pressure reference for it's built-in timing "curve"

There is a check valve in the line running to this "canister", and it prevents it from seeing boost. Any idea what this ignition will do if I pull the check valve and now that "canister" registers positive pressure?

Does it run on a pressure "map" programmed in memory that may or may not include positive pressure readings?

Or is it more of an analog circuit?

Also what about mechanically, will the "canister" rupture?

I will likely leave the check valve in if I don't get any solid responses, and pull it out once the car is running and I'm feeling brave (and possibly have a second ignition computer on hand. lol). Too bad I can hardly get into boost and monitor the timing at the same time to see if I'm getting boost retard or not. I need a little gnome in the engine bay with a timing light.

If it does retard under boost, well, that means I can put a boost bleeder in that tube with a check valve in the orifice so it still gets full vac advance, but under positive pressure I could then adjust the retard down if I wanted.

Any thoughts? I know we're all very busy planning our 16V strokers, but this could be some interesting info.

Thanks for the insight!

Hey CaptainBondo, "Wuz Up"

All the U.S. ones that I had seen had the vacuum hose with nothing inbetween Vacuum ign brain and intake [ maybee Canada spec? ]
And are you sure that is a checkvalve? It could posibly be a vacuum delayvalve.
As far as what that ign system will retard under boost will have to be tried.
And retard under boost IS a good thingso if that system dose not retard under boost. Ditch it!
Mr. U 8)

Hey, ya it's definitely a check valve, i blew through it. I'll just pull it then.
And if i'm not getting ign retard under boost (not sure how I'd be able to tell... :?: ) I'll swap the mechanical boost retard distributor from my 240T in.

CaptainBondo said:

Too bad I can hardly get into boost and monitor the timing at the same time to see if I'm getting boost retard or not. I need a little gnome in the engine bay with a timing light.

Click to expand...

I guess you'll have to get the Hulk on the dyno.

hehe.
True enough Mike, now that i think about it, the hulkster will pretty much definitely still be runing that ignition when he goes to the dyno.

So I guess I won't need that gnome after all....